Question

63. Which of the following is an omega 3 fatty acid?

A.   18:0

B.   18:3 Δ^9,12,15  

C.   16:1 Δ⁹

D.   18:2 Δ^9,12

E.   20:4 Δ^5,8,11,14

64. Which of the following is an essential fatty acid?

A.   lauric acid

B.   oleic acid

C.   linoleic acid

D.   linolenic acid

E.   both C and D are essential fatty acids.

Answer 1

63. which of the following is an omega 3 fatty acid.

ans : option - B

i.e, 18:3 9, 12, 15

64. which of the following is an essential fatty acid ?

Ans: Option - D.

i.e, alpha-linolenic acid

explanation:

• Omega 3 fatty acids are poly unsaturated fatty acids with a double bond C=C at the third carbon atom from the end of the carbon chain.
• the fatty acid shave two ends, the carboxylic acid end(-COOH), which is considered as the beginning of the chain, thus "alpha" , and the methy end(-CH3) which is considered as the tail of chain, thus "Omega", the double bond is at omega minus 3
• Omega 3 fatty acids that are important in human psysiology are alpha-linolenic acid (18:3,n-3 ALA) , eicoSapentanoic acid (20:5, n-5, EPA) and docosahexanoic acid (22:6, n-3, DSA). these three polyunsaturated have either 3,5 or 6 double bonds in a carbon chain of 18,20 or 22 carbon atoms, respectively.
• Essential Fatty acids or EFAs are fatty acids that humans and other animals must ingest because the body requires them for good health but cannot synthesize them.